Refrigerating apparatus



Feb. 9, 1932. v P-M, BRA-[TEN 1,843,913

REFRIGERATING APPARATUS Filed April 50, 1927 @www Patented Feb. 9, 1932UNITED STATES PATENT y OFFICE PHILIP M. BRATTEN, OF FORT WORTH, TEXAS,ASSIGNOR, BY MESNE ASSIGNMENTS, TO FRIGIDAIRE CORPORATION, A CORPORATIONOF DELAWARE REFRIGERATING APPARATUS Application led Apri1 30,

This invention relates to mechanical refrigeration and particularly tomechanically refrigerating devices for cooling various type ofcommercial refrigerator cabinets such as show-case refrigerators.

One object of the invention is to improve the eliiciency of the transferof heat from the circulating air of the cabinet to the metal walls ofthe refrigerating device by substantially preventing accumulation offrost thereon, and to improve the eliiciency of thermal transfer betweenthe metal walls to the refrigerant, whereby refrigeration may beeffected more eciently and economically than heretofore. In the presentinvention this object is accomplished by a novel arrangement of airflues and brine ducts to be described.

Further objects and advantages of the present invention will be apparentfrom the following description, reference being had to the accompanyingdrawings, wherein a preferred form of embodiment of the presentinvention is clearly shown.

In the drawings:

Fig. 1 is vertical longitudinal sectional view of a show-caserefrigerator cabinet equipped with a refrigerating device embodying thepresent invention;

Fig. 2 is a top view partly broken away, of the device; and f Fig. 3 isasectional view on the line 33 of Fig. 2.

In Fig. 1, 20 designates a cabinethaving solid insulating walls 21, 22and 23 and other insulating walls provided by dead air spaces between aplurality of plates of glass 2 4 and 25. A partition 26 Adivides theinterior of the cabinet into a cooling compartment 28 and a food orother display compartment 27.

The refrigerating device 30 includes a shell brine tank made oftin-plated copper or galvanized iron and formed to provide a. main brinechamber, reservoir or body portion 31 and a sheet metal shell or shells,the walls of which provide relatively large air flues 35, 36 and 37.These shell type walls are hollow to provide relatively narrow brineducts or chambers 32, 33 and 34 which communicate with the body portion3l.

1927. Serial No. 187,929.

The body portion or chamber 31 is provided with a tightly fittingremovable cover 3S and encloses a cooling unit herein shown as anevaporator comprising a header or boiler 10 connected with refrigerantducts 4l. One end of the boiler 40 extends through an opening 42 in theoutside wall of the chamber 31 and is secured byl a flanged collar 43, aclamping disc 44 forming one end of the boiler, and by screws 45. Pipes46 and 47 conduct refrigerant respectively into and out of the boiler40. Thechamber and ducts should be filled with brine or other lowfreezing-point liquid up to about one inch below the top of thecontainer and the boiler should not be located too low in the chamber31, otherwise only the brine at the lower levels will effectivelycirculate and be cooled. Preferably the top of the boiler should vbeabout one inch below the level of the brine.

It has been found that with a cooling unit located 10W in a deep tank,the brine above the unit does not cool down to the tem erature desired,it remaining above the reezing point even when the rest of the brine maybe at or below freezing temperature.

The boiler 40 should beilevel in order that the float valve therein (notshown), which controls the flow of refrigerant to the unit, may operateproperly. This is done by metal wedges 60 adapted to rest upon thebottom wall of the tank 31 and to engage the lower portions of theloop-ducts 4,1. The wedges 60 may be secured in the desired positiony bysoldering. 'f

The device 30 is supported above the bottom of the cooling chamber 28and is spaced from the chamber walls and baiiie 26 so that air lmaycirculate freely around the device as well as through its flues.Preferably, the

combined surface of the exposed vertical walls of the device should atleast be equal to the exposed surface of the block of ice which would berequired to cool the cabinet. Bv providing relatively narrow brine ductsarid relatively large iiue openings, a relativemore than approximatelytwo-thirds of the cubical content of the cooling chamber 28, and may beslightly less if necessary to provide at least three inches of spacebetween the walls of the device and the cooling chamber walls so thatair may circulate freely about and through the unit. The matter ofclearance is important, because frosting of the tank and ducts tends todecrease the clearance and might even close it off entirely, preventingfree circulation of the air. Unless the air can circulate freelyadjacent the walls of the refrigerating device, it can not absorb theheat from the air. For the same reason the flue openings should berelatively wide.

The circulation of air within the cabinet is indicated roughly by thearrows 50, 51, 52 and 53. Shelves or other baffles (not shown) may beprovided in the food chamber 27 for securing a fairly even distributionof the air circulating therein.

If more than one refrigerating device is used in a cooling chamber, atleast four inches and preferably six inches should be left between thedevices for circulation and to prevent the space from being stopped upwith frost.

One of the features of the present invention is the use of such arelatively large metal, heat-absorbing surface adjacent which the airmay circulate freely, that it is possible to effect satisfactoryrefrigeration by brine or other heat transfer medium working attemperatures higher than ermissible in brine tanks used heretofore. ingthe active period of operation of the refrigerating machine frost maycollect upon the metal surface, these surfaces will be defrosted duringthe idle periods of the machine. Thus hindrance by frost to the transferof heat to the metal surfaces is much less than in case of brine tanksused heretofore.

Another feature is the circulation of brine through relatively narrowducts between the metal, heat-absorbing surfaces. Substantially all ofthe brine which is cooled by the evaporator is caused to circulateactively so that heat will be conducted from the metal walls to theevaporator more rapidly than heretofore, with the result that theduration of the active period of the refrigerating machine is reduced.

It is therefore apparent that refrigeration can be obtained moreeconomically than heretofore because the heat transferring media, themetal walls and the brine, are caused to o erate more efficiently, andbecause the mac ine is not required to reduce the pressure upon therefrigerant to the low point necessary heretofore, since the averagelbrine temperature is higher.

I have discovered also that a cabinet can be cooled most effectively andeconomically 5 by mechanically refrigerated circulating brine when therefrigerating device containlthough, dur-A ing the brine occupies abouttwo-thirds of the cubic capacity of the cooling compartment or chamberused formerly for receiving ice-blocks, and "when the ducts and lues ofthe unit are so constructed and arranged as to give the maximum coolingsurface with the minimum brine. Large heat transfer surface results inreduction of the space required for` the cooling unit. Therefore, thecompartment for receiving the device may be made smaller. Large finespermit free c irculation of air.

The refrigerating device may be provided with horizontal or vertical uesaccording to the type of refrigerator cabinet with which they areintended to be used. Vertical flues are preferable, owing to the naturaltendency of air to descend on being chilled. However, the invention isnot limited to refrigerating devices or tanks with vertical fiues, as acooling unit with horizontal flues may be used advantageously in sometypes of cabinets; for example, a show-case cabinet not provided with abaffle to separate the food compartment from the cooling compartment.

Where the term brine is used in the specilicat-ion and claims, it refersto any low freezing point liquid or solution which is suitable fortransferring heat from the heat transfer walls of the refrigeratingdevice to the evaporator.

As an example of construction of one form of the invention, if the tankand ducts are made of sheet metal sufficiently thin to permit making thejoints by lock-seaming and soldering, I prefer to provide ducts only oneinch or less wide. If heavier sheet material is required on account ofthe size of the cooling unit, and the joints must therefore be riveted,the ducts may be tworinches wide to allow for introducing riveting toolsbetween the metal sheets forming the ducts. There is no object inmakinof the ducts wider than one inch except to facilitate manufacture.Generally, the brine ducts should be from about one to two inches wideand the fines preferably at least four times as wide as the ducts.

Vhile the form of embodiment of the present invention as hereindisclosed, constitutes a preferred form, it is to be understood thatother forms might be adopted, all coming vithm the scope of the claimswhich fol- What is claimed is as follows:

1. A cooling device for refrigerators comprising, a tank including abody portion adapted to contain brine, and a plurality of shell typehollow walls forming narrow circulating ducts communicating with thebody portion, said walls providing one or more fines for circulatingair, and a cooling unit within the body portion for cooling the brine.

2.-A cooling device for refrigerators comprising, a tank including abody portion adapted to contain brine, and a plurality of verticallyextending shell type hollow walls forming narrow circulating ductscommunieating with the body portion, said walls providing one or morevertically extending Hues for circulating air, and a cooling unit withinthe body portion for cooling the brine.

3. A cooling device for refrigerators comprising, a tank including abody portion` adapted to contain brine, and a plurality of shell typehollow walls forming narrow circulating ducts communicating with thebody portion, said walls extending in a plurality of directions from thebody portion and providing a plurality of Hues for circulating air, anda cooling unit within the bod portion for cooling the brine.

4. A cooling device for a refrigerator comprising a sheet metal shellforming a main chamber for brine, an evaporator' within the chamber forcooling the brine therein, certain walls of said shell being hollow andforming relatively narrow chambers, said narrower chambers branchingfrom and communicating with the main brine chamber and arrangedto form aHue for cooling circulating air.

5. A cooling device for a refrigerator com- Aprising a sheet metal shellforming a main chamber for brine, an evaporator within the chamber forcooling the brine therein, certain walls of said shell being hollow andforming relatively narrow chambers, said narrower chambers branchingfrom and com'- municating with the main brine chamber, said hollow wallsbeing arranged to provide a plurality of Hues, one of said walls be- 1ngcommon to a plurality of said Hues.

6. A cooling device for a refrigerator comprising a sheet metal shellforming a main chamber for brine, an evaporator within the chamber forcooling the brine therein, certain walls of said shell being hollow andforming relatively narrow' chambers, said narrower chambers branchingfrom and communicating with the main brine chamber and arranged to forma Hue for cooling circulating `a1r, the cross sectional area oftherefrigerating mediumvchambers formed by the hollowwalls being less thancross sectional area of the Hue formed by such walls.

rising a tank including a main brine cham.

er adapted to contain brine, and a plurality of shell type hollow wallsforming narrow circulating ducts communicating with the main chamber,saidw walls extending in a plurality of directions from the chamber andproviding ra Hue for circulating air, and aV cooling unit within themain chamber for cooling the brine.

9. A cooling device for refrigerators comprising a tank including a mainbrine chamber adapted to contain brine, and a plurality of shell typehollow walls forming narrow circulating ducts communicating with themain chamber, said walls providing one or more Hues for circulating airand a cooling unit within the main chamber for cooling the brine, thecro'ss sectional area of the circulating ducts formed by the hllow wallsbeing less than the cross sectional area of the Hue formed by suchWalls. l

In testimony whereof hereto ailix my signature.

PHILIP M. BRATTEN.

chamber for brine, an evaporator within the chamber for cooling thebrine therein, certain walls of said shell being hollow and formingrelatively narrow chambers, said narrower chambers branching from andcommunicating with the main brine chamber, said hollow walls beingarranged to provide a plurality of Hues, one of said walls being commonto a plurality of said Hues, the cross sectional area oftherefrige'rating chambers formed by the hollow walls being less than i

